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The Journal of Physical Chemistry. B Jun 2009The study of elastic properties of microbial and mammalian cells using atomic force microscopy, with force-sensitivity as high as pico-Newtons and spatial resolution of...
Real-time nanomechanical and topographical mapping on live bacterial cells-Brevibacterium casei under stress due to their exposure to Co2+ ions during microbial synthesis of Co3O4 nanoparticles.
The study of elastic properties of microbial and mammalian cells using atomic force microscopy, with force-sensitivity as high as pico-Newtons and spatial resolution of a few nanometers, is proving to be a great tool for the real-time observation of the effects of drugs, biomolecules, metal ions, and nanoparticles on cell physiology in their natural environment. It has been shown that the Young's modulus of the cell surfaces is extremely sensitive to the surrounding environment. Recently, a broad array of microbes have been used successfully to synthesize nanocrystals of several metal and metal oxides in a controlled manner at room temperature after exposing them to various metal ion precursors. However, so far there is no report on the fate of their elastic properties and cell topography etc. during and after their exposure to the metal ions during the microbial synthesis of nanomaterials. Additionally, this information is also found to be extremely relevant to areas such as bioremediation, bioleaching, and biomineralization, where it is important to study the direct influence on the cell physiology in the presence of metal ions. Here, we report, for the first time, the use of AFM force-distance curves on live cells, to directly monitor (in real time) the changes in the surface-topography, surface-adhesion, indentation-depth, and Young's modulus of a metal-tolerant marine bacterium, Brevibacterium casei, isolated from the coast of the Arabian Sea, after its exposure to the Co2+ ions during the process of biosynthesis of nanoparticles. We earlier reported that this bacterium is capable of using the cobalt acetate as a precursor to synthesize protein-functionalized Co3O4 nanoparticles with very high crystallinity. Our study indicates a significant change in the morphology as well as elastic and adhesive properties of the Brevibacterium casei, where we found an increase in the adhesive properties and the indentation depth of the bacterial surfaces and a decrease in the cell stiffness after several hours of exposure to the cobalt acetate. We have discussed both qualitative and quantitative analysis of the force-spectroscopy data in detail.
Topics: Bacterial Adhesion; Brevibacterium; Cobalt; Elastic Modulus; Microscopy, Atomic Force; Nanoparticles; Oxides; Time Factors
PubMed: 19438181
DOI: 10.1021/jp902698n -
Colloids and Surfaces. B, Biointerfaces Nov 2009Polyhydroxyalkanoates (PHAs) are natural, biodegradable polymers accumulated by bacteria under nutritional exhausted condition where carbon source is in excess. A gram...
Polyhydroxyalkanoates (PHAs) are natural, biodegradable polymers accumulated by bacteria under nutritional exhausted condition where carbon source is in excess. A gram positive bacterium (designated strain SRKP2) that potentially accumulated polyhydroxybutyrate (PHB) was isolated from dairy industrial waste. From its morphological and physiological properties and nucleotide sequence of its 16S rRNA, it was suggested that strain SRKP2 was similar to Brevibacterium casei. PHAs were synthesized from a medium containing dairy waste, yeast extract and sea water. The synthesized PHAs were characterized by FT-IR as Polyhydroxybutyrate (PHB). Response surface methodology was applied to optimize the production of PHB. From the optimized medium the yield of PHB was found to be 2.940 g/L. Here we report the direct use of dairy waste and sea water as potential sources for the production of PHB. Produced PHB was used to synthesize nanoparticles using solvent displacement technique.
Topics: Analysis of Variance; Brevibacterium; Culture Media; Dairying; Green Chemistry Technology; Hydroxybutyrates; Industrial Waste; Microscopy, Fluorescence; Nanoparticles; Polyesters; Spectroscopy, Fourier Transform Infrared; Time Factors
PubMed: 19700268
DOI: 10.1016/j.colsurfb.2009.07.029 -
Microbiology Resource Announcements Dec 2023We report here the draft genome sequences of ( = 1), ( = 1), ( =1), spp. ( = 5), ( = 3), and isolated from high-touch surfaces in washrooms at a post-secondary...
We report here the draft genome sequences of ( = 1), ( = 1), ( =1), spp. ( = 5), ( = 3), and isolated from high-touch surfaces in washrooms at a post-secondary institution.
PubMed: 37971276
DOI: 10.1128/MRA.00910-23 -
International Journal of Food... Mar 2019In order to encourage Western populations to increase their consumption of vegetables, we suggest turning legumes into novel, healthy foods by applying an old,...
In order to encourage Western populations to increase their consumption of vegetables, we suggest turning legumes into novel, healthy foods by applying an old, previously widespread method of food preservation: fermentation. In the present study, a total of 55 strains from different microbial species (isolated from cheese or plants) were investigated for their ability to: (i) grow on a emulsion containing 100% pea proteins and no carbohydrates or on a 50:50 pea:milk protein emulsion containing lactose, (ii) increase aroma quality and reduce sensory off-flavors; and (iii) compete against endogenous micro organisms. The presence of carbohydrates in the mixed pea:milk emulsion markedly influenced the fermentation by strongly reducing the pH through lactic fermentation, whereas the absence of carbohydrates in the pea emulsion promoted alkaline or neutral fermentation. Lactic acid bacteria assigned to Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis and Lactobacillus casei species grew well in both the pea and pea:milk emulsions. Most of the fungal strains tested (particularly those belonging to the Mucor and Geotrichum genera) were also able to grow on both emulsions. Although most Actinobacteria and Proteobacteria did not compete with endogenous microbiota (Bacillus), some species such as Hafnia alvei, Acinetobacter johnsonii and Glutamicibacter arilaitensis grew strongly and appeared to restrict the development of the endogenous microbiota when the pea emulsion was inoculated with a combination of three to nine strains. In the mixed emulsions, lactic fermentation inhibited Actinobacteria and Proteobacteria (e.g. Brevibacterium casei, Corynebacterium casei, Staphylococcus lentus) to the greatest extent but also inhibited Bacillus (e.g. Bacillus subtilis and Bacillus licheniformis). Overall, this procedure enabled us to select two microbial consortia able to colonize pea-based products and positively influence the release of volatile compounds by generating a roasted/grilled aroma for the 100% pea emulsion, and a fruity, lactic aroma for the 50:50 pea:milk emulsion. Moreover, the fermentation in the pea-based emulsions reduced the level of hexanal, which otherwise leads to an undesired green pea aroma. Our present results show how the assembly of multiple microbial cultures can help to develop an innovative food product.
Topics: Adult; Animals; Cheese; Colony Count, Microbial; DNA, Bacterial; Emulsions; Fermentation; Firmicutes; Food Microbiology; Hafnia alvei; Humans; Lactobacillus plantarum; Lacticaseibacillus rhamnosus; Lactococcus lactis; Lactose; Microbial Consortia; Middle Aged; Milk; Odorants; Pea Proteins; Pisum sativum; RNA, Ribosomal, 16S; Volatile Organic Compounds; Young Adult
PubMed: 30690292
DOI: 10.1016/j.ijfoodmicro.2019.01.012 -
Journal of Orthopaedic Research :... Jul 2017Modular megaprostheses are known for high infection rates followed by high rates of revisions. Microbial biofilms growing adherently on prosthetic surfaces may inhibit...
Modular megaprostheses are known for high infection rates followed by high rates of revisions. Microbial biofilms growing adherently on prosthetic surfaces may inhibit the detection of the pathogens causing prosthetic joint infections. We sought to answer the following questions: Does sonication culture (SC) improve the microbiological diagnosis of periprosthetic infections of megaprostheses compared to conventional tissue culture (TC)? Which pathogens were detected on the surface of megaprostheses with either SC or TC and do the findings help to identify low-grade infections? Included were 31 patients with modular megaprostheses, whose implant had been explanted due to suspected joint infection or revision surgery. SCs were performed according to the protocol by Trampuz et al. The diagnosis of infection was evaluated according to the definition of the Musculoskeletal Infection Society. The sensitivity of SC was 91.3% compared to 52.2% for TC and the specificity was 100% for SC and TC (p = 0.004). Under preoperative antibiotic therapy, the sensitivity of SC was 83.3% while the sensitivity of TC was 50%. Without preoperative antibiotic therapy the sensitivity of SC was 100% compared to 54.5% for TC. In nine cases, SCs detected microorganisms, while TC was negative. Detected bacteria were Staphylococcus epidermidis in four, Micrococcus species in one, Finegoldia magna in one, Brevibacterium casei in one, Pseudomonas fluorescens in one, and Enterococcus faecium in one. SC is a reliable method for dislodging pathogens from orthopedic implants. The SC of modular megaprostheses showed significantly higher pathogen detection than the periprosthetic TC, especially for low virulence pathogens. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1383-1387, 2017.
Topics: Humans; Prosthesis-Related Infections; Sonication; Tissue Culture Techniques
PubMed: 27572456
DOI: 10.1002/jor.23406 -
Systematic and Applied Microbiology Jan 2007Amplified ribosomal DNA restriction enzyme analysis (ARDRA), pulsed field gel electrophoresis (PFGE) and ribotyping were used to differentiate among 24 strains of...
Amplified ribosomal DNA restriction enzyme analysis (ARDRA), pulsed field gel electrophoresis (PFGE) and ribotyping were used to differentiate among 24 strains of Brevibacterium linens, Brevibacterium casei and Brevibacterium epidermidis obtained from type culture collections or isolated from various smear ripened cheeses. ARDRA was applied to the 16S rDNA. B. linens was shown to be a quite heterogenic group with 2 to at least 4 copies of rrn operons per strain with aberrant nucleotide sequences. AccI gave genus specific restriction patterns and was used to separate Brevibacterium from Corynebacterium species. The expected species specificity of TaqI applied to B. linens type culture strains, but not to all strains isolated from cheese. By AvaI restriction, B. casei and B. linens were differentiated from B. epidermidis and the orange pigmented Arthrobacter casei, a new species of coryneform bacteria; by XmnI restriction, B. linens and B. epidermidis were differentiated from B. casei. One of 4 B. linens genotypes could not be distinguished from B. casei by this method. Here, the typical orange B. linens pigments were used for classification, which was confirmed by partial sequencing of the 16S rDNA.
Topics: Arthrobacter; Bacterial Typing Techniques; Brevibacterium; Cheese; DNA, Ribosomal; Electrophoresis, Gel, Pulsed-Field; Pigmentation; RNA, Ribosomal, 16S; Restriction Mapping; Ribotyping
PubMed: 16624515
DOI: 10.1016/j.syapm.2006.02.008 -
Clinical Microbiology and Infection :... May 2004Brevibacterium has been reported as a rare cause of implanted-device infection. In two cases of recurrent Brevibacterium casei bacteraemia associated with infection of...
Brevibacterium has been reported as a rare cause of implanted-device infection. In two cases of recurrent Brevibacterium casei bacteraemia associated with infection of surgically implanted intravascular devices, relapse occurred 2 and 5 months, respectively, after completion of therapy with vancomycin via the infected catheter. A second intravenous antibiotic therapy course by the antibiotic-lock technique led to bacteriological cure in one patient. Molecular typing results demonstrated that the recurrent bacteraemia was caused by the same strain. Implanted-device removal may be necessary, in addition to appropriate antibiotics, for successful management of such infections.
Topics: Actinomycetales Infections; Adult; Anti-Bacterial Agents; Bacteremia; Brevibacterium; Catheters, Indwelling; Device Removal; Equipment Contamination; Female; Humans; Male; Vancomycin
PubMed: 15113328
DOI: 10.1111/j.1469-0691.2004.00857.x -
Journal of Hazardous Materials Oct 2010Chromate [Cr(VI)] and azo dyes are common pollutants which may co-exist in some industrial effluents. Hence studies of biological treatment of industrial wastewater...
Chromate [Cr(VI)] and azo dyes are common pollutants which may co-exist in some industrial effluents. Hence studies of biological treatment of industrial wastewater should include investigation of the co-removal of these two pollutants. Brevibacterium casei, which can reduce Cr(VI) in the presence of the azo dye Acid Orange 7 (AO7) under nutrient-limiting condition, was isolated from a sewage sludge sample of a dyeing factory. Response surface methodology, which is commonly used to optimize growth conditions for food microorganisms to maximize product(s) yield, was used to determine the optimal conditions for chromate reduction and dye decolourization by B. casei. The optimal conditions were 0.24 g/L glucose, 3.0 g/L (NH(4))(2)SO(4) and 0.2 g/L peptone at pH 7 and 35 degrees C. The predicted maximum chromate reduction efficiencies and dye decolourization were 83.4+/-0.6 and 40.7+/-1.7%, respectively. A new mechanism was proposed for chromate reduction coupling with AO7 decolourization by B. casei. Under nutrient-limiting condition, AO7 was used as an e(-) donor by the reduction enzyme(s) of B. casei for the reduction of Cr(VI). The resulted Cr(III) then complexed with the oxidized AO7 to form a purple coloured intermediate.
Topics: Azo Compounds; Brevibacterium; Chromates; Color; Coloring Agents; Culture Media; Electrons; Hot Temperature; Hydrogen-Ion Concentration; Mass Spectrometry; Oxidation-Reduction; Spectrophotometry, Atomic
PubMed: 20656406
DOI: 10.1016/j.jhazmat.2010.06.106 -
Journal of Clinical Microbiology Jun 2004Six coryneforms isolated from blood and dialysate fluid were phenotypically similar to Brevibacterium casei, but 16S rRNA gene sequencing and DNA-DNA hybridization...
Six coryneforms isolated from blood and dialysate fluid were phenotypically similar to Brevibacterium casei, but 16S rRNA gene sequencing and DNA-DNA hybridization indicate that they belong to a new species for which the name Brevibacterium sanguinis is proposed.
Topics: Base Sequence; Brevibacterium; Humans; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S
PubMed: 15184484
DOI: 10.1128/JCM.42.6.2829-2832.2004 -
Journal of Bioscience and Bioengineering Jan 2005Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and... (Comparative Study)
Comparative Study
Halophilic and non-halophilic bacteria subjected to osmotic downshock, from 0.7 M NaCl to deionized water, were examined for their survival, with the uptake and utilization of the cyclic amino acid ectoine, one of the representative compatible solutes, being taken into account. The uptake of ectoine added externally and survival of the cells were monitored as a function of incubation time in the presence and absence of NaCl. The halophilic Brevibacterium sp. JCM 6894 and B. epidermidis JCM 2593 actively accumulated ectoine regardless of the presence of NaCl, which led to cell survival. Brevibacterium casei JCM 2594 belonging to the same Brevibacterium species, however, revealed Na+-dependence of its uptake activity of ectoine. Non-halophilic Escherichia coli K-12 did not accumulate ectoine, and thereby this strain failed to survive irrespective of whether NaCl was present. The physiological meanings of the downshock procedure are discussed in connection with the uptake and the subsequent utilization of ectoine.
Topics: Amino Acids, Diamino; Apoptosis; Brevibacterium; Cell Proliferation; Cell Survival; Escherichia coli; Heat-Shock Response; Metabolic Clearance Rate; Osmotic Pressure; Species Specificity; Water-Electrolyte Balance
PubMed: 16233755
DOI: 10.1263/jbb.99.61